Jakob Stoklund Olesen 53e000bac3 Better handling of dead super registers in LiveVariables. We used to do this: ...

CALL ... %RAX<imp-def>
   ... [not using %RAX]
   %EAX = ..., %RAX<imp-use, kill>
   RET %EAX<imp-use,kill>

Now we do this:

   CALL ... %RAX<imp-def, dead>
   ... [not using %RAX]
   %EAX = ...
   RET %EAX<imp-use,kill>

By not artificially keeping %RAX alive, we lower register pressure a bit.

The correct number of instructions for 2008-08-05-SpillerBug.ll is obviously
55, anybody can see that. Sheesh.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@97838 91177308-0d34-0410-b5e6-96231b3b80d8

2010-03-05 21:49:17 +00:00

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